1074 A PATHOGENIC FACTOR IN CONGENITAL CMV INFECTIONS (C-CMV)

Abstract

To better define the role of primary (PMI) and recurrent (RMI) CMV infections in the pathogenesis of C-CMV a longitudinal study of both middle (MI) and low (LI) income pregnant women was initiated. Susceptibility to CMV at the onset of pregnancy was 39% (1630 of 4130) in MI women and 16% (399 of 2375) in LI women. In these two groups, newly acquired infections were confirmed in 0.7% and 1.5% of serosusceptibles, respectively. Interestingly, independent from economic strata, PMI lead to C-CMV in only 36% of cases. However C-CMV after a recurrence in previously infected women occurred in 0.2 and 1.4% of infants born to MI and LI women respectively. This dissimilarity accounts for the major difference in the overall incidence of C-CMV between these two populations (0.2% vs. 0.8%).From this and previous studies we have identified 19 and 17 infants whose C-CMV resulted from primary and recurrent maternal infections respectively. Thus far, disease has occurred in only 3 infants (one fatal) and all belong to the former group. Also increased IgM in cord sera and the quantity of CMV shed in urine of these infants up to 4 months of age, were significantly higher among those infected after PMI.These observations indicate that PMI does not always result in C-CMV nor does it cause acute or delayed morbidity in all infected infants. Yet, its pathogenic potential may be significantly higher than RMI.